By Tuesday, Michel Kilo, a Syrian dissident, was leaning wearily over his coffee at a Left Bank cafe, wondering: Where was the global outrage? Where was the outpouring that came after the same terrorist groups unleashed horror in Brussels and here in Paris? In a supposedly globalized world, do nonwhites, non-Christians and non-Westerners count as fully human?

“All this crazy violence has a goal,” Mr. Kilo, who is Christian, said: to create a backlash against Muslims, divide societies and “make Sunnis feel that no matter what happens, they don’t have any other option.”

This is not the first time that the West seems to have shrugged off massacres in predominantly Muslim countries. But the relative indifference after so many deaths caused by the very groups that have plagued the West is more than a matter of hurt feelings.

One of the primary goals of the Islamic State and other radical Islamist groups is to drive a wedge between Sunni Muslims and the wider world, to fuel alienation as a recruiting tool. And when that world appears to show less empathy for the victims of attacks in Muslim nations, who have borne the brunt of the Islamic State’s massacres and predatory rule, it seems to prove their point.

Hira Saeed of Ottawa asked on Twitter why Facebook had not activated its Safety Checkfeature after recent attacks as it did (Free-Pr-Online.com) for Brussels, Paris and Orlando, Fla., and why social media had not been similarly filled with the flags of Turkey, Bangladesh and Iraq. “The hypocrisy is the western world is strong,” she wrote.

The global mood increasingly feels like one of atavism, of retreat into narrower identities of nation, politics or sect, with Britain voting to leave the European Union and many Americans supporting the nativist presidential campaign of Donald J. Trump.

The violence feeds a growing impulse among many in the West to fear Muslims and Arabs, which has already prompted a political crisis over immigration that, in turn, has buttressed extremists’ goals. Europe is convulsing over a movement to reject refugees from Syria and Iraq, who are themselves fleeing violence by jihadists and their own governments.

It is in Syria and Iraq that the Islamic State has established its so-called caliphate, ruling overwhelmingly Muslim populations with the threat of gruesome violence. The group has killed Muslims in those countries by the thousands, by far the largest share of its victims.

When Islamic State militants mowed down cafe-goers in Paris in November, people across the world adorned public landmarks and their private Facebook pages with the French flag — not just in Europe and the United States, but also, with an empathy born of experience, in Syria and Iraq.

But over the past week, Facebook only activated its Safety Check feature, which allows people in the vicinity of a disaster to mark themselves safe, after the attack on the Istanbul airport.

The flags of Iraq, Saudi Arabia, Turkey and Bangladesh have not been widely projected on landmarks or adopted as profile pictures. (Photographs on social media showed that in Bosnia and Herzegovina, one of Europe’s two majority-Muslim countries, the Turkish flag was beamed onto a bridge in Mostar, the scene of sectarian killings in the 1990s.) Some wonder if part of the reason is that three of those flags bear Islamic symbols or slogans.

“More deaths in Iraq in the last week than Paris and Orlando combined but nobody is changing their profile pics, building colours, etc.,” Kareem Rahaman wrote on Twitter.

There are some understandable reasons for the differing reactions. People typically identify more closely with places and cultures that are familiar to them. With Iraq, there is also a degree of fatigue, and a feeling that a bombing there is less surprising than one in Europe.

Deadly attacks have been a constant in Iraq after years of American occupation, followed by a sectarian war in which Sunni and Shiite militias slaughtered civilians of the opposite sect. Still, while terrorist attacks in Europe may feel more surprising to the West — though they have become all too common there, too — that does not explain the relative indifference to attacks in Istanbul, Saudi Arabia or Bangladesh.

“That’s what happens in Iraq,” Sajad Jiyad, a researcher in Iraq who rushed to the scene of the Baghdad bombing and found that one of his friends had died there, wrote on his own blog. “Deaths become just statistics, and the frequency of attacks means the shock doesn’t register as it would elsewhere, or that you have enough time to feel sad or grieve.”

In the Muslim world, the partly sectarian nature of conflicts shades people’s reactions, producing a kind of internal sympathy gap. People from one sect or political group often discount or excuse casualties from another.

In Iraq, the Islamic State took root within an insurgency against the country’s Shiite-led government, and Shiite militias fighting it have been accused of brutality as well. In Syria, it is just one menace; many more Syrians have been killed by the government’s attacks on areas held by Sunni insurgents, including rebel groups opposed to the Islamic State.

Mr. Jiyad added that the Islamic State was “hoping to incite a reaction and a spiral into endless violence,” and that Iraqis played into that when they mourned more for their own sect than for others.

In the West, though, there is a tendency in certain quarters, legitimized by some politicians, to conflate extremist Islamist militants with the Muslim societies that are often their primary victims, or to dismiss Muslim countries as inherently violent.

“Either Iraqi blood is too cheap or murder is normalized,” Sayed Saleh Qazwini, an Islamic educator in Michigan, wrote on Twitter.

In Paris, a rainbow flag hangs on the Hotel de Ville, memorializing the 49 people gunned down at a gay nightclub in Orlando last month. But in a corner shop on Monday, the woman who served me had no such sympathy for the Middle East.

When she asked where I lived, and I told her Beirut, Lebanon, she exclaimed about the violence in the region. Unable to quickly explain that there is a lot more than just violence happening there, I said: “Yes, there are a lot of problems. What can one do?”

“Exterminer les islamistes,” she said grimly. Exterminate: a strong word. Islamists: a broad category of people.

Mr. Kilo, who spent years in the prisons of the Syrian government and opposes both it and the Islamic State, said his life in Paris had changed since November. Speaking Arabic is now suspect. He sees fear in French people’s eyes when they see Syrians.

“I’m afraid, too,” he said. “Someone could blow himself up anytime.”

He has written an article that will be published in the newspaper Al Araby Al Jadeed, titled “The Curse of Syria.”

The failure of empathy is broader than the Islamic State, he said; it extends to the international community’s unwillingness or inability to stop the slaughter of the Syrian civil war, which began with protests for political change.

“If we lose all humanity,” Mr. Kilo said, “if you allow the slaughter of a nation for five and a half years, after all the leaders of the international community declared the right of these people to revolt against their government, then expect Islamic State — and many other Islamic States in other forms and shapes.”